The invention provides a tetracarboxylic acid heavy calcium carbonate powder fluorescent whitening agent. The tetracarboxylic acid heavy calcium carbonate powder fluorescent whitening agent is characterized in that the tetracarboxylic acid heavy calcium carbonate powder fluorescent whitening agent has the following structural formula 1 (please see the formula in the specification). The invention aims at providing the tetracarboxylic acid heavy calcium carbonate powder fluorescent whitening agent and a preparation method and application thereof. The method is simple, the raw material price is low, and the process is green and environment-friendly. Heavy calcium carbonate powder treated by the fluorescent whitening agent has high whiteness degree and brightness, and also has good fluidity and dispersing performance, and the tetracarboxylic acid heavy calcium carbonate powder fluorescent whitening agent is a high-performance fluorescent whitening agent integrating whitening and surface modification.